A computational item is a value used in arithmetic operations. It must be
numeric. If a group item is described with a computational usage, the
elementary items within the group have that usage.
The maximum length of a computational item is 18 decimal digits, except
for a PACKED-DECIMAL item. If the ARITH(COMPAT) compiler option is in
effect, then the maximum length of a PACKED-DECIMAL item is 18 decimal
digits. If the ARITH(EXTEND) compiler option is in effect, then the
maximum length of a PACKED-DECIMAL item is 31 decimal digits.
The PICTURE of a computational item can contain only:
9 One or more numeric character positions
S One operational sign
V One implied decimal point
P One or more decimal scaling positions
COMPUTATIONAL-1 and COMPUTATIONAL-2 items (internal floating-point) cannot
have PICTURE strings.
BINARY Specified for binary data items. Such items have a decimal
equivalent consisting of the decimal digits 0 through 9, plus a
sign. Negative numbers are represented as the two’s complement
of the positive number with the same absolute value.
The amount of storage occupied by a binary item depends on the
number of decimal digits defined in its PICTURE clause:
¦ Digits in PICTURE clause ¦ Storage occupied ¦
¦ 1 through 4 ¦ 2 bytes (halfword) ¦
¦ 5 through 9 ¦ 4 bytes (fullword) ¦
¦ 10 through 18 ¦ 8 bytes (doubleword) ¦
Binary data is big-endian: the operational sign is contained in
the leftmost bit.
BINARY, COMPUTATIONAL, and COMPUTATIONAL-4 data items can be
affected by the TRUNC compiler option. For information about the
effect of this compiler option, see the Enterprise COBOL
PACKED-DECIMAL Specified for internal decimal items. Such an item appears
in storage in packed decimal format. There are two digits for
each character position, except for the trailing character
position, which is occupied by the low-order digit and the sign.
Such an item can contain any of the digits 0 through 9, plus a
sign, representing a value not exceeding 18 decimal digits.
The sign representation uses the same bit configuration as the
4-bit sign representation in zoned decimal fields. For details,
see the Enterprise COBOL Programming Guide.
COMPUTATIONAL or COMP (binary) This is the equivalent of BINARY. The
COMPUTATIONAL phrase is synonymous with BINARY.
COMPUTATIONAL-1 or COMP-1 (floating-point) Specified for internal
floating-point items (single precision). COMP-1 items are 4
COMPUTATIONAL-2 or COMP-2 (long floating-point) Specified for internal
floating-point items (double precision). COMP-2 items are 8
COMPUTATIONAL-3 or COMP-3 (internal decimal) This is the equivalent of
COMPUTATIONAL-4 or COMP-4 (binary) This is the equivalent of BINARY.
COMPUTATIONAL-5 or COMP-5 (native binary) These data items are represented
in storage as binary data. The data items can contain values up
to the capacity of the native binary representation (2, 4, or 8
bytes), rather than being limited to the value implied by the
number of nines in the picture for the item (as is the case for
USAGE BINARY data). When numeric data is moved or stored into a
COMP-5 item, truncation occurs at the binary field size rather
than at the COBOL picture size limit. When a COMP-5 item is
referenced, the full binary field size is used in the operation.
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